1. Field of the Invention
The present invention relates to an exercise wheel that has a stronger returning torque and improved stability while stopping further forward movement of the exercise wheel. The present invention also relates to an exercise wheel that is reduced in a manufacture cost thereof and that prevents radial outward expansion of the torsion springs to thereby prevent damage to the torsion springs resulting from operation of the exercise wheel in the wrong direction.
2. Description of the Related Art
FIGS. 6 and 7 of the drawings illustrates a conventional exercise wheel that includes a housing 1xe2x80x2, two grip rods 2xe2x80x2, a main gear 3xe2x80x2, two roller pairs 4xe2x80x2, and two torsion springs 5xe2x80x2. The housing 1xe2x80x2 includes a compartment with a downwardly facing opening and aligned holes 11xe2x80x2 on two sides thereof into which the grip rods 2xe2x80x2 are mounted. Two stop rods 12xe2x80x2 are mounted inside the housing 1xe2x80x2. The main gear 3xe2x80x2 is mounted to the grip rods 2xe2x80x2 and includes a peg 32xe2x80x2 on each side thereof. Each roller pair 4xe2x80x2 includes two rollers 41xe2x80x2 connected by a shaft 42xe2x80x2 that has teeth 421xe2x80x2 formed on an outer periphery thereof for meshing with teeth 31xe2x80x2 of the main gear 3xe2x80x2. Each torsion spring 5xe2x80x2 includes two ends 52xe2x80x2 and 53xe2x80x2 that are attached to an associated peg 32xe2x80x2 and an associated stop rod 12xe2x80x2, respectively.
When in use, the user bends downward and grasps the grip rods 2xe2x80x2 to make roller pairs 4xe2x80x2 to roll on the ground. During rolling of the roller pairs 4xe2x80x2, the torsion springs 5xe2x80x2 are tensioned by the main gear 3xe2x80x2 via transmission of the teeth 421xe2x80x2 and 31xe2x80x2. When the main gear 3xe2x80x2 is turned for one turn such that the end 52xe2x80x2 of the torsion spring 51xe2x80x2 bears against the stop rod 12xe2x80x2, and the main gear 3xe2x80x2 and the roller pairs 4xe2x80x2 are thus stopped. The torsion springs 51xe2x80x2 may return the exercise wheel to its initial position.
Nevertheless, assembly of the exercise wheel is time-consuming and costly, as a force must be provided to overcome the torsion springs 5xe2x80x2 while assembling the main gear 3xe2x80x2. In addition, when the user operates the main gear 3xe2x80x2 in the wrong direction, the torsion springs 5xe2x80x2 might be damaged, as the torsion springs are twisted in the wrong direction, as shown in FIG. 8.
It is an object of the present invention to provide an exercise wheel that may limit the maximum travel of the exercise wheel.
It is another object of the present invention to provide an exercise wheel that may prevent damage to the torsion springs when the exercise wheel is operated in the wrong direction.
It is a further object of the present invention to provide an exercise wheel that provides higher returning force to the wheel assemblies of the exercise wheel.
In accordance with a first aspect of the invention, an exercise wheel comprises:
a housing having two sides,
two grip rods secured to the two sides of the housing, respectively,
a chassis housed by the housing and including two side walls, and
two wheel assemblies each comprising:
a shaft mounted between the side walls of the chassis,
two wheels mounted in the housing and connected by the shaft to thereby allow rotational movement of the wheels, and
a torsion spring having a coil portion mounted around the shaft, a first end securely attached to one of the wheels, and a second end securely attached to one of the housing and the chassis,
whereby rotational movement of the wheels in a forward direction is stopped when the torsion spring is twisted such that the coil portion of the torsion spring is in contact with an outer periphery of the shaft.
A tube may be mounted between the shaft and the coil portion of the torsion spring. A sleeve may be mounted around the coil portion of the torsion spring to prevent radial outward expansion of the coil portion when the wheels are moved in a direction opposite to the forward direction. Each wheel of each wheel assembly includes an engaging groove for engaging with an associated end of the sleeve.
In accordance with a second aspect of the invention, an exercise wheel comprises: a housing,
a chassis housed by the housing and including two side walls,
a grip rod extended through the housing and the side walls of the chassis, and
a wheel assembly comprising:
two wheels mounted between the side walls of the chassis and around the grip rod to thereby allow rotational movement of the wheels, and
a torsion spring having a coil portion mounted around the grip rod, a first end securely attached to one of the wheels, and a second end securely attached to one of the housing and the chassis,
whereby rotational movement of the wheels in a forward direction is stopped when the torsion spring is twisted such that the coil portion of the torsion spring is in contact with an outer periphery of the grip rod.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.